Messages from the Assistant Principal
A focus on Learning, Collaboration & Improving Student Outcomes
Mental Mathematics Strategies (Part 2)
In the last school newsletter, I summarised the meaning behind ‘mental strategies’ in Mathematics, the importance of making connections and provided some practical suggestions and website for parents to support the development of mental strategies at home.
Developing children’s mental strategies provides them with the tools to be able to use and apply basic ideas to solve much more complex problems.
Below are five reasons outlining the importance of building children’s mental strategies.
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Mathematics is not just about getting the right answer
Correct answers are necessary, but how you got them is more important, specifically for young children. As teachers we want to make sure our young children do not become ‘stuck’ using strategies such as counting by ones forever. The only way to find this out is to ask them. Being able to share your ideas and understanding and to prove how you know something works or is true is an important aspect in mathematics.
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Flexible strategies are needed in other areas of mathematics
Understanding how numbers work and what to do with them mentally means you have a ‘bank’of ways to work things out, especially when things go wrong. If I know mentally that 16 is the same as 10 + 6, I can use that to work out 8 x 16. I can work out 8 x 10 then 8 x 6 then add them together. If I also didn’t know what 8 x 6 was, I could either do 4 x 6 and double the answer or do 3 x 8 and double the answer.
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There are times when it is ‘quicker’ more efficient not to use an algorithm
When there are just ‘random’ numbers to add like 2345 + 137 + 84 + 9, it makes sense to write them as a list and use an algorithm to find the answer. But say my question was 4002 - 3998, in this example it is much more efficient (faster) for my brain to count up from 3998 to 4002 and get an answer of 4, than to write those numbers out as an algorithm, then use ‘borrowing’ or ‘trading’ to find the answer.
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Knowing how to solve maths questions in your brain builds confidence
As mentioned above, many children and adults know how to ‘do’ algorithms but do not feel confident in their maths ability and may not like maths at all. As teachers, we want children to look forward to learning about maths and to feel success in both working out answers and knowing why it works. Not being reliant on an algorithm (especially for small facts to 20 like 12+ 7) gives children confidence that they can work it out using their brain. Working hard pays off and all children can be successful in mathematics, as can all adults. You may just not feel that way, yet.
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If students know how numbers work first, the algorithm won’t be difficult to understand
The subtraction examples provided above (26 - 19) clearly shows a child that does not understand how numbers work. Children that may still be counting by ones to work out addition and subtraction should not be exposed to algorithms. Children who know how numbers work and know that 26 is made up of 2 tens and 6 ones and know that they can break 26 into 10 and 16 to then subtract the 9, won’t have difficulty if introduced to the procedure of the algorithm. However, questions involving 2-digit numbers like 26 - 19 should be solved mentally (e.g. starting with the 19 and adding 7 to make 26). In NSW, algorithms are introduced with 3 and 4-digit addition and subtraction.
With every best wish,
Nikki Norley (Assistant Principal)
